SAN is Intel SSR212MC2R with SRCSAS144E raid controller (as far as I can tell this is rebadged LSI MegaRAID). This is using Open-E iSCSI R3 (yes I know, old hardware and old OS)

A drive has failed in a Volume Group (3 x 500GB SATA). I replaced the drive and it now shows as "unconfigured good" in the MegaRAID storage manager (ver 9.00.0100) The VG is running, but in degraded state.

Right click on the unconfigured good drive gives various options including "replace missing drive" - If I take this option, will it begin rebuilding the raid data or is there more to it? This VG hosts a number of Citrix VMs, so wiping it will be a Very Bad Thing.

I do have good and current backups, but would still like to recover as opposed to reload.

My suggestion is that if you have any doubt of your backups, make another. As I am sure many others will chime in on this, RAID 5 has a chance of destroying the array during the rebuild. I am not familiar with that particular raid controller so I won't comment on the option to rebuild it, though I would think that it is.

However, if your company has some off hours that you could do the rebuild, that might be the best time, just in case.

On the brighter side, if it does toast the array and you have a spare drive, it would be a perfect time to change to RAID 10.

HP has always listed RAID 1 as RAID 1+0. The theory is that RAID 10 with a one length stripe is RAID 1. So it is all semantics at that point. If you assign RAID 10 to a two disk set you get RAID 1. The difference is that you can expand it without having to rename the RAID type.

It's just a naming convention thing. It still works exactly as expected.

When you click on Replace Missing drive does it immediately come up with error or does it go Offline - if offline then that's good and then you should right click again and choose "Start rebuild"

Just a note, I'm glad you installed the MSM as it is not good to power off a RAID in a degraded state when it supports hot swap just in case disk does not come back online and then you would be royally screwed.

6 Replies

My suggestion is that if you have any doubt of your backups, make another. As I am sure many others will chime in on this, RAID 5 has a chance of destroying the array during the rebuild. I am not familiar with that particular raid controller so I won't comment on the option to rebuild it, though I would think that it is.

However, if your company has some off hours that you could do the rebuild, that might be the best time, just in case.

On the brighter side, if it does toast the array and you have a spare drive, it would be a perfect time to change to RAID 10.

1st Post

Right click on the unconfigured good drive, select "replace missing drive" is the correct option. The drive status then changes to "offline". Right clicking on that drive now gives the option to rebuild. I took that option and I'll know in about three hours if it's worked or not.

A bit scary not knowing exactly what will happen, first time is always the worst.

Right click on the unconfigured good drive, select "replace missing drive" is the correct option. The drive status then changes to "offline". Right clicking on that drive now gives the option to rebuild. I took that option and I'll know in about three hours if it's worked or not.

A bit scary not knowing exactly what will happen, first time is always the worst.